E risk of HCV vertical and needlestick transmissions [42,43]. Concurrent with a recent transition in the risk from transfusion to IDU, the prevalence of 6a is increasing while 1b is decreasing. As we know, 1b has been regarded to be more associated with HCV transmission via blood transfusion while 6a typically linked to IDU and sexual transmission [12]. In this study, all blood donors were asked to answer a standardized questionnaire before blood donations which listed all the knownrisk factors. Donors would be Title Loaded From File excluded when having a history of transfusion of blood or blood products, IDU, receiving a tattoo, ear or body piercing, surgery, or other invasive medical procedures. Follow-up studies were also Title Loaded From File performed on those who were HCV viremic. However, only a small proportion of the donors confessed having these risks (data not shown). It is concerning that subtype 6a might have spread to the general population via the IDU network or through illegal sexual workers. In this regard, a significantly higher proportion of male, found among donors infected with 6a than with other HCV genotypes, is implicative. We found that the percentage of male donors who were HCV viremic is about 3.8 times as many as that of the female donors (79.2 versus 20.8 ), while in initial screening a total of 707 voluntary blood donors were detected to be positive for anti-HCV among whom the male/female ratio is about 2.5 (503/204). It has been reported that women are more likely to clear the virus spontaneously after acute infection [44,45]. This can be interpreted that men are more likely to develop chronic hepatitis than women and continue to be HCV viremic. The interpretation helps to explain why male donors tended to have higher levels of HCV RNA than female donors (6.06 versus 5.69 log 10 IU/ml), which is consistent with 18325633 the results from a very recent large-scale study based on a multi-ethnic group of IDUs [29]. We firmly believe that the outcomes of HCV infection among women are much better than among men. In support of this belief, there exist additional lines of evidence: 1) HCV is more likely to infect men. In the USA, the prevalence of anti-HCV among men was twice as that among women [4]. In one of our recent studies, a significantly higher antiHCV rate has also been revealed among male donors than among female [26]. 2) The male gender has been considered to be one of the key factors in promoting the progression of hepatic fibrosis as a result of chronic HCV infection [46]. 3) Female hormones have been identified to function as inhibitors against HCV. It has been reported that the estrogen receptor alpha (ESR1) can promote HCV replication by interaction with the NS5B protein, an RNAdependent RNA polymerase encoded by HCV genome [47,48], while this interaction can be abolished by 17-estradiol or tamoxifen [48,49]. Comparing with premenopausal female patients, postmenopausal female have faster progression of hepatic fibrosis, but the latter can be delayed by hormone replacement therapy with estrogen and progesterone. In summary, for the first time 11967625 we reported the relatively high viral loads of HCV among voluntary blood donors who were infected with subtype 6a strains. We also correlated the measured viral loads with detected HCV genotypes and the donors’ gender. We found that donors infected with genotype 1 and 6 had significantly higher viral loads than those with genotype 2 and 3, and male donors had significantly higher viral loads than female donors.E risk of HCV vertical and needlestick transmissions [42,43]. Concurrent with a recent transition in the risk from transfusion to IDU, the prevalence of 6a is increasing while 1b is decreasing. As we know, 1b has been regarded to be more associated with HCV transmission via blood transfusion while 6a typically linked to IDU and sexual transmission [12]. In this study, all blood donors were asked to answer a standardized questionnaire before blood donations which listed all the knownrisk factors. Donors would be excluded when having a history of transfusion of blood or blood products, IDU, receiving a tattoo, ear or body piercing, surgery, or other invasive medical procedures. Follow-up studies were also performed on those who were HCV viremic. However, only a small proportion of the donors confessed having these risks (data not shown). It is concerning that subtype 6a might have spread to the general population via the IDU network or through illegal sexual workers. In this regard, a significantly higher proportion of male, found among donors infected with 6a than with other HCV genotypes, is implicative. We found that the percentage of male donors who were HCV viremic is about 3.8 times as many as that of the female donors (79.2 versus 20.8 ), while in initial screening a total of 707 voluntary blood donors were detected to be positive for anti-HCV among whom the male/female ratio is about 2.5 (503/204). It has been reported that women are more likely to clear the virus spontaneously after acute infection [44,45]. This can be interpreted that men are more likely to develop chronic hepatitis than women and continue to be HCV viremic. The interpretation helps to explain why male donors tended to have higher levels of HCV RNA than female donors (6.06 versus 5.69 log 10 IU/ml), which is consistent with 18325633 the results from a very recent large-scale study based on a multi-ethnic group of IDUs [29]. We firmly believe that the outcomes of HCV infection among women are much better than among men. In support of this belief, there exist additional lines of evidence: 1) HCV is more likely to infect men. In the USA, the prevalence of anti-HCV among men was twice as that among women [4]. In one of our recent studies, a significantly higher antiHCV rate has also been revealed among male donors than among female [26]. 2) The male gender has been considered to be one of the key factors in promoting the progression of hepatic fibrosis as a result of chronic HCV infection [46]. 3) Female hormones have been identified to function as inhibitors against HCV. It has been reported that the estrogen receptor alpha (ESR1) can promote HCV replication by interaction with the NS5B protein, an RNAdependent RNA polymerase encoded by HCV genome [47,48], while this interaction can be abolished by 17-estradiol or tamoxifen [48,49]. Comparing with premenopausal female patients, postmenopausal female have faster progression of hepatic fibrosis, but the latter can be delayed by hormone replacement therapy with estrogen and progesterone. In summary, for the first time 11967625 we reported the relatively high viral loads of HCV among voluntary blood donors who were infected with subtype 6a strains. We also correlated the measured viral loads with detected HCV genotypes and the donors’ gender. We found that donors infected with genotype 1 and 6 had significantly higher viral loads than those with genotype 2 and 3, and male donors had significantly higher viral loads than female donors.
